Electrical diagnostic system for refrigeration apparatus

ABSTRACT

A diagnostic system for use with refrigeration apparatus and the like for selectively indicating the operability condition of different electrical components thereof. The indicating apparatus is mounted to the refrigeration apparatus and includes a selector switch for selectively placing the apparatus in a normal operation mode or in a test mode. A lamp provided for normal illumination of the interior of the refrigeration apparatus cabinet is selectively utilized by the testing apparatus as an indicator of the operability condition of the selected component.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to refrigeration apparatus and in particular tomeans for selectively indicating the operability condition of electricalcomponents of refrigeration apparatus.

2. Description of the Prior Art

In the diagnosis of electrical circuitry of refrigeration apparatus andthe like, a serviceman utilizes conventional electrical test equipment,such as meters, indicating lamps, etc., by suitable isolation of thedifferent electrical components and application of test voltagesthereto. Substantial skill is necessary on the part of the serviceman toproperly ascertain the operability condition of the differentcomponents.

To permit such servicing diagnosis in a facilitated manner, apparatushas been developed including a separable connector which is connectedinto the circuitry of the apparatus to permit testing of the operabilitycondition of individual circuit components by means of a testingapparatus removably connected to the connector. Such apparatus enablesthe serviceman to more expeditiously make direct electrical connectionsto the isolated components of the apparatus, thereby facilitating theservicing of the apparatus.

Because of the relatively high cost of service in connection withappliances, such as refrigeration apparatuses and the like, it has beenfound desirable to permit the owner of the appliance to perform at leastthe diagnostic phase of the servicing so that the servicing may beeffected by the owner or facilitated by a serviceman as a result of thediagnostic information obtained by the owner prior to requesting theservice. The servicing of the apparatus by the owner in connection witha number of appliances may be facilitated by the use of plug-incomponents so that by means of suitable diagnosis, efficient and lowcost servicing of the apparatus may be effected by the owner himself.

One example of means for indicating damage in the circuit of arefrigerator, or power failure in the service lines thereto, isillustrated in U.S. Pat. No. 2,385,525 of Graham S. McCloy. In theMcCloy patent, the lamp which is normally energized when the door to therefrigerator food compartment is opened is connected in the apparatus sothat a failure of the light to be de-energized during a defrosting cycleof the timer mechanism is used to indicate a failure in the clockmechanism or its associated circuitry. Thus, McCloy uses the lamp toindicate the defrosting of the refrigerator. In addition, McCloyprovides a pair of additional lamps for illuminating a control panel.During a defrosting operation, energization of the normal cabinetilluminating lamp and one of the additional control indicating lamps isde-energized to indicate the defrosting operation. A signal lamp isprovided in addition for indicating that electrical power is beingprovided to the refrigerator. The light from the signal lamp isdominated by the light from the control lamp and is preferably of acolor different from the color of the control lamp.

U.S. Pat. No. 3,736,765 of George B. O'Dell, discloses the use of aconnector means for checking and diagnosing the quality and operation ofthe components of a household appliance by means of test equipmentconnected to the appliance through the connector means. The connectormeans has a plurality of mating terminals which are separable toelectrically isolate the electrical components of the appliance so thatthe components can be individually tested.

SUMMARY OF THE INVENTION

The present invention comprehends an improved diagnostic system forselectively indicating the operability condition of the electricalcomponents of an appliance, such as a refrigeration apparatus. Thecondition indicating apparatus is provided integrally with therefrigeration apparatus so that a determination of the operabilitycondition of the components may be effected at any time as by the userof the apparatus or by a serviceman in the servicing of the apparatus.

The indicating apparatus includes a selector switch permitting therefrigeration apparatus to function in the normal operational mode orselectively be rearranged so as to permit the testing of the individualelectrical components. In the testing mode, the illuminating means ofthe refrigeration apparatus normally provided for illuminating therefrigerated space is utilized as an indicating means. Thus, theindicating apparatus is extremely simple and economical of constructionutilizing a simple selector switch and modified circuitry in theapparatus while yet permitting the improved facilitated testing of theapparatus components.

The testing apparatus eliminates the need for special tools orequipment, thereby permitting the user to effect testing of theoperability condition of the different electrical components without theneed for expensive supplementary test equipment. Further, the test ofthe apparatus is facilitated by servicemen as the testing can beeffected quickly and simply without the need for providing access to theelectrical components to effect the testing procedure. As the testingcircuitry is installed in the manufacturing facilities, correctconnection of the testing apparatus in the testing mode is assured.

Among the electrical components which may be tested in an apparatus,such as a refrigeration apparatus, are the defrost timer switch,refrigerated space thermostat, defrost bimetallic thermostat, defrostheater, and mullion and stile heaters. Where the refrigeration apparatusincludes an automatic ice maker, the water valve solenoid may further betested by the improved testing apparatus of the invention.

BRIEF DESCRIPTION OF THE DRAWING

Other features and advantages of the invention will be apparent from thefollowing description taken in connection with the accompanying drawingwherein:

FIG. 1 is a perspective view of a refrigeration apparatus provided witha diagnostic system embodying the invention; and

FIG. 2 is a schematic wiring diagram illustrating the electricalcircuitry of the diagnostic system.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In the exemplary embodiment of the invention as disclosed in thedrawing, a diagnostic system generally designated 10 is provided for usein an apparatus, such as an appliance, in selectively indicating theoperability condition of electrical components thereof. In illustratingthe invention, the diagnostic system is shown for indicating thecondition of the components of a refrigeration apparatus generallydesignated 11 illustratively comprising a refrigerator-freezerapparatus. As shown in FIG. 1, the refrigerator-freezer apparatus 11includes a cabinet 12 defining a freezer space 13 and an above-freezingrefrigerator space 14 selectively closed by doors 15 and 16,respectively.

An automatic ice maker 17 may be provided in freezer space 13 to whichwater is automatically supplied through a suitable solenoid operatedwater valve 18 carried in a lower portion of the cabinet 12. In theillustrated embodiment, refrigeration of spaces 13 and 14 is effected byflowing air as by means of a fan 19 in heat exchange relationship withan evaporator 20 disposed in the rear wall 21 of cabinet 12 at the rearof space 13. A defrost bimetal control 22 is associated with evaporator20 for controlling the defrosting operation which is effected in aconventional manner by a defrost heater 23 automatically controlled by adefrost timer 24 provided in a console 25 at the rear of refrigeratorspace 14 subjacent the mullion 26 separating spaces 13 and 14.

The mullion may be provided with an electric heater 27 and the stile maybe provided with a stile heater 28.

The refrigeration circuit, including evaporator 20, further includes aconventional compressor 29 and condenser 30. A condenser fan 31 isprovided for discharging heat from the condenser to atmosphere in theconventional manner.

Refrigerator space 14 is illuminated, upon opening of the door 16, by apair of lamps 32 and 33 carried by console 25. A suitable switch 34 maybe provided on mullion 26 for controlling the lights 32 and 33 as afunction of the opening and closing of door 16. Console 25 may furtherinclude an air duct inlet 35 for delivering refrigerated air fromfreezer space 13 into refrigerator space 14. Operation of therefrigeration apparatus is automatically controlled by a thermostat 36also carried by the console 25.

As discussed above, the present invention is concerned with thedetermination of the operability condition of the different electricalcomponents of apparatus 11 and comprehends the provision of a diagnosticswitch generally designated 37 carried by the console 25 for selectivearrangement of the apparatus in a normal operation mode or in adiagnostic test mode. The selector switch is accessible at the rear ofrefrigerator space 14, as shown in FIG. 1, permitting facilitatedselective indication of the operability condition of the apparatuscomponents without the need for external test apparatus or access to thecomponents themselves.

Referring now more specifically to the schematic wiring diagram of FIG.2, selector switch 37 is arranged to permit the normal operation of therefrigeration apparatus with the switch set in the 0 position, i.e.,with the wipers 37a of the two stages 37b and 37c connected to the 0contact. Power may be provided in the apparatus from a conventionalpower supply including input leads L1 and L2. The apparatus may beprovided with a conventional terminal block 38 through which the powersupply leads are fed. Light switch 34 is connected from power supplylead L2 to contact 0 of selector switch stage 37c which, in turn, isconnected to each of contacts 4, 6, 7 and 8 thereof. Switch 34 isfurther connected in series with lamp 32 to power supply lead L1 so thatlamp 32 is illuminated whenever door 16 is in the open position ofFIG. 1. Each of the electrical components, including the defrost timerswitch 24a, the thermostat 36, the defrost bimetallic thermostat switch22, the defrost heater 23, the automatic ice maker water valve solenoid18a, and the mullion and stile heaters 27 and 28, is connected in thecircuit in the normal manner to provide the normal functioning thereofin the automatic operation of the refrigeration apparatus.

To determine the operability condition of these different components,the user selectively repositions the selector switch 37 to any one ofthe eight additional positions wherein the corresponding component isisolated and placed in series with the lamp 33 to provide the desireddiagnostic test thereof. Thus, with the switch wipers 37a in the firsttest position contacting contacts 1, the defrost timer switch 24a isisolated and placed in series with lamp 33. More specifically, in thefirst position, an electrical connection is made from power supply leadL2 through the moving contact 24b of switch 24a to the lower, fixedcontact 24c thereof to contact 1 of selector switch stage 37c. Wiper 37athereof is connected in series with lamp 33 to wiper 37a of front stage37b which, through its connection to contact 1 thereof, is connected topower supply lead L1. In making this test, the defrost timer 24 is setto the "Defrost" position wherein switch 24a should be closed to fixedcontact 24c so that if lamp 33 is not energized with the switch 37 inthe first position, a failure of the defrost timer switch 24a isindicated.

When the defrost timer switch 24a is set to provide normal refrigerationoperation of the apparatus, moving contact 24b closes with an upper,fixed contact 24d. This closing of the switch is tested by setting theselector switch 37 in the second position wherein the wipers 37a engagecontacts 2. In this arrangement of the selector switch, the circuitthrough switch 24a is from power supply lead L2 to contact 24d tocontact 2 of the rear stage 37c and through wiper 37a thereof and lamp33 to the first stage wiper 37a and, thus, to power supply lead L1.

Thermostat switch 36 is tested by setting the selector switch 37 in thethird position. As the thermostat switch functions only in the normaloperation of the apparatus, the circuit is from power supply lead L2through switch 24a which, in this mode, has moving contact 24b connectedto fixed contact 24d. With the thermostat switch 36 closed, power isdelivered to rear stage contact 3 and thence through the wiper 37a tolamp 33, and front stage wiper 37a to power supply lead L1.

Defrost bimetal switch 22 is tested with the selector switch in thefourth position. The circuit is from power supply lead L2 through lightswitch 34 to contact 4 of the rear stage 37c, through wiper 37a thereofand thence through lamp 33 and wiper 37a and contact 4 of switch stage37b to bimetal switch 22 and thence to power supply lead L1.

In testing bimetal switch 22, it is necessary that the switch besubjected to a low temperature suitable for closing the switch. If therefrigerator has not been operating so as to provide this temperature,some external means of cooling must be provided.

The testing of defrost heater 23 utilizes alternative testing with theswitch in either of position 5 or position 6. When the bimetal switch 22is open, a check of heater 23 is effected by positioning the selectorswitch in position 5 wherein the circuit is from power supply lead L2through switch 24a with the switch in the Defrost arrangement whereinmoving contact 24b is closed to fixed contact 24c, and to one side ofthe resistor 23. The other side of the heater resistor is connected tocontact 5 of switch stage 37c and wiper 37a thereof in contact therewithto lamp 33 and wiper 37a to power supply lead L1.

In the event that bimetallic switch 22 is closed, the operabilitycondition of heater resistor 23 may be tested by positioning theselector switch 37 in the sixth position wherein the circuit through theheater resistor is from power supply lead L2 through light switch 34 tocontact 6 of selector switch stage 37c, wiper 37a to lamp 33 and wiper37a of the front stage 37b to fixed contact 6 thereof and thence throughresistor 23 and the closed bimetallic switch 22 to power supply lead L1.

The water valve solenoid 18a is tested with the selector switch inposition No. 7. In this position, power is supplied from power supplylead L1 through the solenoid 18a to contact 7 of front stage 37b,through wiper 37a and lamp 33 to wiper 37a of rear stage 37c, and fromcontact 7 of stage 37c to light switch 34 and power supply lead L1.Solenoid 18a is of relatively high impedance and, thus, in this test,lamp 33 burns relatively dimly whereas in each of the other tests, theindication that the circuit component is good comprises a brightillumination of the lamp.

To test the mullion and stile heaters 27 and 28, switch 37 is set in theeighth position. The circuit thus established is from power supply leadL2, light switch 34, contact 8 of the rear stage 37c through wiper 37ato lamp 33, through wiper 37a of front stage 37b to contact 8 thereofand through heaters 27 and 28 to power supply lead L1. As the resistanceof the heaters is relatively high notwithstanding the parallelconnection thereof, lamp 33 will glow relatively dimly in indicatingcontinuity through the two heaters and very dimly if one of the heatersis open-circuited. If both are open-circuited, obviously, the lamp willnot be energized.

Thus, by simple manipulation of the selector switch 37, normal operationof the refrigeration apparatus may be obtained or alternatively, any oneof the connected electrical components may be tested simply and quicklywithout requiring any special equipment, instruments, or the like. Noelectrical test connections to the apparatus need be made as all areintegrally provided therein at the time of manufacture. The location ofthe selector switch 37 is closely adjacent the indicating lamp 33 sothat ready reference to the lamp may be made while concurrentlyoperating the selector switch to the desired selective positions.

The following electrical diagnosis chart may thusly be utilized inconnection with the illustrated embodiment. As will be obvious to thoseskilled in the art, other appliances and electrical components thereofmay be provided with similar selector switch diagnostic system meanswithin the scope of the invention.

    __________________________________________________________________________    ELECTRICAL DIAGNOSIS CHART                                                                          TEST SETTING                                                                  TEST                                                                          SWITCH                                                                             DEFROST  THERMOSTAT                                                                            COMPONENT                         PROBLEM PROBABLE CAUSE                                                                              POS. TIMER POSITION                                                                         POSITION                                                                              O.K. IF:                          __________________________________________________________________________                                                BOTH                              HIGH REF.                                                                             DEFROST TIMER SWITCH                                                                        1    DEFROST  ON OR OFF                                                                             BRIGHT LIGHT                                                                  AND                               AND FRZR.             2    REFRIGERATE                                                                            ON OR OFF                                                                             BRIGHT LIGHT                              THERMOSTAT    3    REFRIGERATE                                                                            ON      BRIGHT LIGHT                      TEMPS. OR                                                                             DEFROST BIMETAL                                                                             4    EITHER   ON OR OFF                                                                             BRIGHT LIGHT                              (See Note 4)                                                          NO COOLING                                  EITHER                                    DEFROST HEATER                                                                              5    DEFROST  ON OR OFF                                                                             BRIGHT LIGHT                                                                  OR                                                      6    REFRIGERATE                                                                            ON OR OFF                                                                             BRIGHT LIGHT                      NO ICE  I.M. WATER VALVE                                                                            7    EITHER   ON OR OFF                                                                             DIM LIGHT                         CABINET MULLION & STILE                                                                             8    DEFROST  OFF     DIM LIGHT                         EXTERIOR                                                                              HEATERS                                                               SWEATING                                                                      HIGH    INTERIOR FAN  0    REFRIGERATE                                                                            ON      INTERIOR AIR FLOW                 REFR. &                                                                       FRZR.   EXTERIOR FAN  0    REFRIGERATE                                                                            ON      EXTERIOR AIR FLOW                 TEMPS.  COMPRESSOR    0    REFRIGERATE                                                                            ON      INTERIOR COOLING                  OR                                                                            NO                                                                            COOLING                                                                       __________________________________________________________________________     Notes:                                                                        (1) OPERATE THE DOOR SWITCH PRIOR TO START OF TESTING TO INSURE RIGHT SID     LIGHT IS OPERATING -- ON AND OFF.                                             (2) DEFROST TIMER MUST BE CHECKED FIRST TO INSURE THAT A DEFECTIVE TIMER      WILL NOT AFFECT OTHER RESULTS.                                                (3) RETURN TEST SWITCH TO NON-NUMBERED POSITION WHEN CHECKS ARE COMPLETED     (4) DEFROST BIMETAL MUST BE COLD TO CHECK OPERATION: IF NECESSARY, COOL       BIMETAL WITH FREON.                                                      

The foregoing disclosure of specific embodiments is illustrative of thebroad inventive concepts comprehended by the invention.

Having described the invention, the embodiments of the invention inwhich an exclusive property of privilege is claimed are defined asfollows:
 1. In a refrigeration apparatus having a plurality ofelectrical components, apparatus for selectively indicating theoperability condition of the components, comprising testing controlmeans carried by said apparatus including selector switch means andcircuit means interconnecting said switch means and one of saidelectrical components to cause said one component to define an indicatormeans for selectively (a) causing normal operation of the apparatus, or(b) separately connecting said components to said indicator means forindicating the operability condition of the different components.
 2. Therefrigeration apparatus of claim 1 wherein said indicator meanscomprises means for illuminating the refrigeration apparatus in saidnormal operation of the apparatus.
 3. The refrigeration apparatus ofclaim 1 wherein said refrigeration apparatus defines a cabinetselectively closed by a door, and said indicator means comprises meansfor illuminating the interior of the cabinet when said door is disposedin an open position.
 4. The refrigeration apparatus of claim 1 whereinsaid one of said electrical components comprises a switch forcontrolling a defrost operation of said refrigeration apparatus.
 5. Therefrigeration apparatus of claim 1 wherein said refrigeration apparatusincludes a defrost timer and one of said electrical components comprisesa defrost switch arranged to be closed by the timer in the defrostoperation of the refrigeration apparatus.
 6. The refrigeration apparatusof claim 1 wherein said refrigeration apparatus includes a defrost timerand one of said electrical components comprises a refrigeration switcharranged to be closed by the timer in the refrigeration operation of therefrigeration apparatus.
 7. The refrigeration apparatus of claim 1wherein one of said electrical components comprises a thermostatresponsive to the temperature condition of the apparatus for controllingrefrigeration operation of the apparatus.
 8. The refrigeration apparatusof claim 1 wherein one of said components comprises a bimetallic switchresponsive to a temperature condition of the apparatus for controlling adefrost operation of the apparatus.
 9. The refrigeration apparatus ofclaim 1 wherein one of said components comprises a defrost heater inseries with a bimetallic control switch and said testing control meansincludes means for connecting said defrost heater to different portionsof the selector switch for selective testing of the defrost heateroperability condition (a) with the bimetallic control switch closed, and(b) with the bimetallic control switch open.
 10. The refrigerationapparatus of claim 1 wherein said apparatus includes an ice makermechanism and one of said components comprises a solenoid controlling awater supply valve for selective delivery of water to said ice makermechanism.
 11. The refrigeration apparatus of claim 1 wherein saidapparatus includes a cabinet and one of said components comprises anelectric heater for selectively heating a portion of the cabinet.
 12. Ina refrigeration apparatus having a plurality of electrical components,and a cabinet defining a space to be refrigerated, apparatus forselectively indicating the operability condition of the components,comprising:lamp means mounted within said cabinet for illuminating saidspace; and a testing control means carried by said cabinet includingselector switch means and circuit means interconnecting said switchmeans and said lamp means for selectivelya. causing normal cabinetilluminating operation of the lamp means, or b. separately connectingsaid components to said lamp means whereby said lamp means may beutilized for indicating the operability condition of the differentcomponents.
 13. The refrigeration apparatus of claim 12 wherein saidselector switch is mounted to said cabinet adjacent said lamp means. 14.The refrigeration apparatus of claim 12 including a plurality of lampsilluminating said space, and said lamp means comprises a single one ofsaid lamps.
 15. The refrigeration apparatus of claim 12 wherein saidrefrigeration apparatus further includes additional lamp means forilluminating said space irrespective of the positioning of said selectorswitch.